Confusing eval on move 40 / 41

I played a 10 minute game and the eval afterwards confused me can someone explain it to me on move 40 it says I am -7.7 then the computer recommends Nxc4 then the eval goes to -1.5 even though it is the recommended move then when my opponent made the recommended move then my eval shot back up to -8.7 how can the eval drop and raise so drastically considering I was never in trouble as my knight can always go back in time to stop the pawn? lichess.org/n0i1OTyW/black#0

Was this an OTB game? Computer is for some reason weaker with imported games according to my personal experience.

Isn't -7.7 or minus anything an eval for Black's advantage? When it's minus -20 or under, its close to detecting checkmate for black.

Turn on infinite analysis in the analysis board settings and the problem should disappear.